Merge pull request #1120 from oragono/master+relaymsg

Initial RELAYMSG implementation

conventional.yaml

@@ -143,6 +143,19 @@ server:
     # if this is true, the motd is escaped using formatting codes like $c, $b, and $i
     motd-formatting: true
 
+    # relaying using the RELAYMSG command
+    relaymsg:
+        # is relaymsg enabled at all?
+        enabled: true
+
+        # which character(s) are reserved for relayed nicks?
+        separators: "/"
+
+        # can channel operators use RELAYMSG in their channels?
+        # our implementation of RELAYMSG makes it safe for chanops to use without the
+        # possibility of real users being silently spoofed
+        available-to-chanops: true
+
     # addresses/CIDRs the PROXY command can be used from
     # this should be restricted to localhost (127.0.0.1/8, ::1/128, and unix sockets),
     # unless you have a good reason. you should also add these addresses to the
@@ -515,6 +528,7 @@ oper-classes:
             - "local_unban"
             - "nofakelag"
             - "roleplay"
+            - "relaymsg-anywhere"
 
     # network operator
     "network-oper":
@@ -734,7 +748,7 @@ fakelag:
 roleplay:
     # are roleplay commands enabled at all? (channels and clients still have to
     # opt in individually with the +E mode)
-    enabled: true
+    enabled: false
 
     # require the "roleplay" oper capability to send roleplay messages?
     require-oper: false

default.yaml

@@ -170,6 +170,19 @@ server:
     # if this is true, the motd is escaped using formatting codes like $c, $b, and $i
     motd-formatting: true
 
+    # relaying using the RELAYMSG command
+    relaymsg:
+        # is relaymsg enabled at all?
+        enabled: true
+
+        # which character(s) are reserved for relayed nicks?
+        separators: "/"
+
+        # can channel operators use RELAYMSG in their channels?
+        # our implementation of RELAYMSG makes it safe for chanops to use without the
+        # possibility of real users being silently spoofed
+        available-to-chanops: true
+
     # addresses/CIDRs the PROXY command can be used from
     # this should be restricted to localhost (127.0.0.1/8, ::1/128, and unix sockets),
     # unless you have a good reason. you should also add these addresses to the
@@ -543,6 +556,7 @@ oper-classes:
             - "local_unban"
             - "nofakelag"
             - "roleplay"
+            - "relaymsg-anywhere"
 
     # network operator
     "network-oper":
@@ -762,7 +776,7 @@ fakelag:
 roleplay:
     # are roleplay commands enabled at all? (channels and clients still have to
     # opt in individually with the +E mode)
-    enabled: true
+    enabled: false
 
     # require the "roleplay" oper capability to send roleplay messages?
     require-oper: false

gencapdefs.py

@@ -93,6 +93,12 @@ CAPDEFS = [
         url="https://ircv3.net/specs/extensions/multi-prefix-3.1.html",
         standard="IRCv3",
     ),
+    CapDef(
+        identifier="Relaymsg",
+        name="draft/relaymsg",
+        url="https://github.com/ircv3/ircv3-specifications/pull/417",
+        standard="proposed IRCv3",
+    ),
     CapDef(
         identifier="Rename",
         name="draft/rename",

irc/caps/defs.go

@@ -7,7 +7,7 @@ package caps
 
 const (
 	// number of recognized capabilities:
-	numCapabs = 26
+	numCapabs = 27
 	// length of the uint64 array that represents the bitset:
 	bitsetLen = 1
 )
@@ -53,6 +53,10 @@ const (
 	// https://github.com/ircv3/ircv3-specifications/pull/398
 	Multiline Capability = iota
 
+	// Relaymsg is the proposed IRCv3 capability named "draft/relaymsg":
+	// https://github.com/ircv3/ircv3-specifications/pull/417
+	Relaymsg Capability = iota
+
 	// Rename is the proposed IRCv3 capability named "draft/rename":
 	// https://github.com/SaberUK/ircv3-specifications/blob/rename/extensions/rename.md
 	Rename Capability = iota
@@ -131,6 +135,7 @@ var (
 		"draft/event-playback",
 		"draft/languages",
 		"draft/multiline",
+		"draft/relaymsg",
 		"draft/rename",
 		"draft/resume-0.5",
 		"echo-message",

irc/client_lookup_set.go

@@ -165,6 +165,10 @@ func (clients *ClientManager) SetNick(client *Client, session *Session, newNick
 			return "", errNicknameInvalid, false
 		}
 
+		if config.isRelaymsgIdentifier(newNick) {
+			return "", errNicknameInvalid, false
+		}
+
 		if restrictedCasefoldedNicks.Has(newCfNick) || restrictedSkeletons.Has(newSkeleton) {
 			return "", errNicknameInvalid, false
 		}

irc/commands.go

@@ -252,6 +252,10 @@ func init() {
 			minParams:      2,
 			allowedInBatch: true,
 		},
+		"RELAYMSG": {
+			handler:   relaymsgHandler,
+			minParams: 3,
+		},
 		"RENAME": {
 			handler:   renameHandler,
 			minParams: 2,

irc/config.go

@@ -502,6 +502,11 @@ type Config struct {
 		MOTD                    string
 		motdLines               []string
 		MOTDFormatting          bool `yaml:"motd-formatting"`
+		Relaymsg                struct {
+			Enabled            bool
+			Separators         string
+			AvailableToChanops bool `yaml:"available-to-chanops"`
+		}
 		ProxyAllowedFrom     []string `yaml:"proxy-allowed-from"`
 		proxyAllowedFromNets []net.IPNet
 		WebIRC               []webircConfig `yaml:"webirc"`
@@ -1106,6 +1111,17 @@ func LoadConfig(filename string) (config *Config, err error) {
 	}
 	config.Server.capValues[caps.Languages] = config.languageManager.CapValue()
 
+	if config.Server.Relaymsg.Enabled {
+		for _, char := range protocolBreakingNameCharacters {
+			if strings.ContainsRune(config.Server.Relaymsg.Separators, char) {
+				return nil, fmt.Errorf("RELAYMSG separators cannot include the characters %s", protocolBreakingNameCharacters)
+			}
+		}
+		config.Server.capValues[caps.Relaymsg] = config.Server.Relaymsg.Separators
+	} else {
+		config.Server.supportedCaps.Disable(caps.Relaymsg)
+	}
+
 	config.Debug.recoverFromErrors = utils.BoolDefaultTrue(config.Debug.RecoverFromErrors)
 
 	// process operator definitions, store them to config.operators
@@ -1206,6 +1222,19 @@ func (config *Config) getOutputPath(filename string) string {
 	return filepath.Join(config.Server.OutputPath, filename)
 }
 
+func (config *Config) isRelaymsgIdentifier(nick string) bool {
+	if !config.Server.Relaymsg.Enabled {
+		return false
+	}
+
+	for _, char := range config.Server.Relaymsg.Separators {
+		if strings.ContainsRune(nick, char) {
+			return true
+		}
+	}
+	return false
+}
+
 // setISupport sets up our RPL_ISUPPORT reply.
 func (config *Config) generateISupport() (err error) {
 	maxTargetsString := strconv.Itoa(maxTargets)

irc/handlers.go

@@ -2013,6 +2013,16 @@ func messageHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *R
 		if i == maxTargets {
 			break
 		}
+
+		config := server.Config()
+		if config.isRelaymsgIdentifier(targetString) {
+			if histType == history.Privmsg {
+				rb.Add(nil, server.name, ERR_NOSUCHNICK, client.Nick(), targetString, client.t("Relayed users cannot receive private messages"))
+			}
+			// TAGMSG/NOTICEs are intentionally silently dropped
+			continue
+		}
+
 		// each target gets distinct msgids
 		splitMsg := utils.MakeMessage(message)
 		dispatchMessageToTarget(client, clientOnlyTags, histType, msg.Command, targetString, splitMsg, rb)
@@ -2421,6 +2431,72 @@ func rehashHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Re
 	return false
 }
 
+// RELAYMSG <channel> <spoofed nick> :<message>
+func relaymsgHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *ResponseBuffer) (result bool) {
+	config := server.Config()
+	if !config.Server.Relaymsg.Enabled {
+		rb.Add(nil, server.name, "FAIL", "RELAYMSG", "NOT_ENABLED", client.t("RELAYMSG has been disabled"))
+		return false
+	}
+
+	channel := server.channels.Get(msg.Params[0])
+	if channel == nil {
+		rb.Add(nil, server.name, ERR_NOSUCHCHANNEL, client.Nick(), utils.SafeErrorParam(msg.Params[0]), client.t("No such channel"))
+		return false
+	}
+
+	allowedToRelay := client.HasRoleCapabs("relaymsg-anywhere") || (config.Server.Relaymsg.AvailableToChanops && channel.ClientIsAtLeast(client, modes.ChannelOperator))
+	if !allowedToRelay {
+		rb.Add(nil, server.name, "FAIL", "RELAYMSG", "NOT_PRIVED", client.t("You cannot relay messages to this channel"))
+		return false
+	}
+
+	rawMessage := msg.Params[2]
+	if strings.TrimSpace(rawMessage) == "" {
+		rb.Add(nil, server.name, "FAIL", "RELAYMSG", "BLANK_MSG", client.t("The message must not be blank"))
+		return false
+	}
+	message := utils.MakeMessage(rawMessage)
+
+	nick := msg.Params[1]
+	_, err := CasefoldName(nick)
+	if err != nil {
+		rb.Add(nil, server.name, "FAIL", "RELAYMSG", "INVALID_NICK", client.t("Invalid nickname"))
+		return false
+	}
+	if !config.isRelaymsgIdentifier(nick) {
+		rb.Add(nil, server.name, "FAIL", "RELAYMSG", "INVALID_NICK", fmt.Sprintf(client.t("Relayed nicknames MUST contain a relaymsg separator from this set: %s"), config.Server.Relaymsg.Separators))
+		return false
+	}
+
+	channel.AddHistoryItem(history.Item{
+		Type:    history.Privmsg,
+		Message: message,
+		Nick:    nick,
+	}, "")
+
+	// send msg
+	channelName := channel.Name()
+	relayTags := map[string]string{
+		"relaymsg": client.Nick(),
+	}
+	for _, member := range channel.Members() {
+		for _, session := range member.Sessions() {
+			var tagsToUse map[string]string
+			if session.capabilities.Has(caps.Relaymsg) {
+				tagsToUse = relayTags
+			}
+
+			if session == rb.session {
+				rb.AddSplitMessageFromClient(nick, "*", tagsToUse, "PRIVMSG", channelName, message)
+			} else {
+				session.sendSplitMsgFromClientInternal(false, nick, "*", tagsToUse, "PRIVMSG", channelName, message)
+			}
+		}
+	}
+	return false
+}
+
 // RENAME <oldchan> <newchan> [<reason>]
 func renameHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *ResponseBuffer) bool {
 	oldName, newName := msg.Params[0], msg.Params[1]

irc/help.go

@@ -417,6 +417,16 @@ Replies to a PING. Used to check link connectivity.`,
 		text: `PRIVMSG <target>{,<target>} <text to be sent>
 
 Sends the text to the given targets as a PRIVMSG.`,
+	},
+	"relaymsg": {
+		text: `RELAYMSG <channel> <spoofed nick> :<message>
+
+This command lets channel operators relay messages to their
+channel from other messaging systems using relay bots. The
+spoofed nickname MUST contain a forwardslash.
+
+For example:
+	RELAYMSG #ircv3 Mallory/D :Welp, we linked Discord...`,
 	},
 	"rename": {
 		text: `RENAME <channel> <newname> [<reason>]

irc/roleplay.go

@@ -82,7 +82,7 @@ func sendRoleplayMessage(server *Server, client *Client, source string, targetSt
 				if rb.session == session {
 					rb.AddSplitMessageFromClient(source, "", nil, "PRIVMSG", targetString, splitMessage)
 				} else {
-					session.sendSplitMsgFromClientInternal(false, source, "", nil, "PRIVMSG", targetString, splitMessage)
+					session.sendSplitMsgFromClientInternal(false, source, "*", nil, "PRIVMSG", targetString, splitMessage)
 				}
 			}
 		}
@@ -108,7 +108,7 @@ func sendRoleplayMessage(server *Server, client *Client, source string, targetSt
 		cnick := client.Nick()
 		tnick := user.Nick()
 		for _, session := range user.Sessions() {
-			session.sendSplitMsgFromClientInternal(false, source, "", nil, "PRIVMSG", tnick, splitMessage)
+			session.sendSplitMsgFromClientInternal(false, source, "*", nil, "PRIVMSG", tnick, splitMessage)
 		}
 		if away, awayMessage := user.Away(); away {
 			//TODO(dan): possibly implement cooldown of away notifications to users

irc/server.go

@@ -485,6 +485,10 @@ func (server *Server) applyConfig(config *Config) (err error) {
 			return fmt.Errorf("UTF-8 enforcement cannot be changed after launching the server, rehash aborted")
 		} else if oldConfig.Accounts.Multiclient.AlwaysOn != config.Accounts.Multiclient.AlwaysOn {
 			return fmt.Errorf("Default always-on setting cannot be changed after launching the server, rehash aborted")
+		} else if oldConfig.Server.Relaymsg.Enabled != config.Server.Relaymsg.Enabled {
+			return fmt.Errorf("Cannot enable or disable relaying after launching the server, rehash aborted")
+		} else if oldConfig.Server.Relaymsg.Separators != config.Server.Relaymsg.Separators {
+			return fmt.Errorf("Cannot change relaying separators after launching the server, rehash aborted")
 		}
 	}
 

irc/strings.go

@@ -19,6 +19,16 @@ import (
 
 const (
 	precisUTF8MappingToken = "rfc8265"
+
+	// space can't be used
+	// , is used as a separator
+	// * is used in mask matching
+	// ? is used in mask matching
+	// . denotes a server name
+	// ! separates nickname from username
+	// @ separates username from hostname
+	// : means trailing
+	protocolBreakingNameCharacters = " ,*?.!@:"
 )
 
 var (
@@ -138,18 +148,10 @@ func CasefoldName(name string) (string, error) {
 		return "", errStringIsEmpty
 	}
 
-	// space can't be used
-	// , is used as a separator
-	// * is used in mask matching
-	// ? is used in mask matching
-	// . denotes a server name
-	// ! separates nickname from username
-	// @ separates username from hostname
-	// : means trailing
 	// # is a channel prefix
 	// ~&@%+ are channel membership prefixes
 	// - I feel like disallowing
-	if strings.ContainsAny(lowered, " ,*?.!@:") || strings.ContainsAny(string(lowered[0]), "#~&@%+-") {
+	if strings.ContainsAny(lowered, protocolBreakingNameCharacters) || strings.ContainsAny(string(lowered[0]), "#~&@%+-") {
 		return "", errInvalidCharacter
 	}